The present invention relates to a projector.
Projectors are used in various types of facilities, such as home theaters, conference rooms, classrooms, training rooms, amusement halls, exhibition halls, and studios, to project graphics generated by a computer and the like or graphics recorded on a recording medium, such as an optical disc or a magnetic tape, onto a special screen, wall surface, or floor surface. In the prior art, when using a projector, the projector, more specifically, the case of the display device, must be spaced by a few meters from the projection surface (e.g., screen or wall). Thus, an object that blocks the projection light cannot be placed in between the display device and the projection surface. To resolve this problem, techniques for shortening the distance between the case of a projector and a projection surface is being developed. For example, a projector that is now being developed shortens the projection distance by using an aspheric reflection mirror, which enables wide-angle projection (refer to Japanese Laid-Open Patent Publication No. 2004-252049).
A projector that shortens the projection distance will now be discussed with reference to FIG. 9. The projector includes a case 101 and an aspheric reflection mirror 102. When the projector is in use, the aspheric reflection mirror 102 is projected out of a surface 101a of the case 101. When not in use, the aspheric reflection mirror 102 is retracted into the case 101.